Field of Invention
The present invention relates to a display apparatus, in particular to a display apparatus with testing functions. The present invention also relates to a driving circuit and a driving method of the display apparatus.
Description of Related Art
FIG. 1 shows a prior art display apparatus (display apparatus 300) disclosed in US 2013/0328854, wherein a processor 370 monitors the input voltage and the output voltage to determine whether the display voltage VOD is shorted; if yes, the power switching device is turned OFF to cut off the display voltage VOD.
The prior art in FIG. 1 has a drawback that: because this prior art determines whether the display voltage VOD is shorted only by monitoring the input voltage and the output voltage, it requires detecting a large short circuit current to trigger the protection; this prior art cannot effectively detect failure items such as a leakage current whose amount is much smaller than a short circuit current. Other drawbacks of this prior art are that the timing for detecting whether the display voltage VOD is shorted is not very flexible, and that this prior art cannot actively provide and execute various test patterns.
FIG. 2 shows a prior art short-circuit detection circuit (short-circuit detection circuit 10) for a display apparatus disclosed in U.S. Pat. No. 8,643,993, wherein the short-circuit detection circuit 10 detects if the current of the driving switch P1 is overly high and generate a short-circuit detection signal.
The prior art in FIG. 2 has drawbacks that the short-circuit detection circuit 10 can only passively detect if the current of driving switch P1 is overly high within a short window in a cycle period of a display control signal (control signal in the figure); this prior art cannot flexibly determine the detection timings, and cannot actively provide and execute various test patterns.
FIG. 3 shows a prior art display apparatus with over current protection disclosed in U.S. Pat. No. 8,643,993, wherein an over current protection circuit 700 detects an over current of a clock signal which drives the display panel at the leading edge of the clock signal, and takes actions when necessary.
The prior art in FIG. 3 has drawbacks that the over current protection circuit 700 can detect the over current of the clock signal only within a short window; this prior art cannot flexibly determine the detection timings, and cannot actively provide and execute various test patterns.
Compared to the prior arts in FIGS. 1, 2 and 3, the present invention has advantages that various test patterns can be provided to test a display apparatus, at flexible timings during non-display driving period. Hence the present invention can detect various more types of failure items and has a higher sensitivity for failure detection, compared to all the aforementioned prior arts.